Facebook uses 10,000 Blu-ray Discs to create petabytes of "cold storage"
30 petabytes worth of Blu-rays! :eek:
Source: Ars Technica
Facebook has built a prototype cold storage system that uses Blu-ray Discs instead of traditional drives. "The Blu-ray system reduces costs by 50 percent and energy use by 80 percent compared with its current cold-storage system, which uses hard disk drives," the IDG News Service reported, based on a talk given by Facebook VP of infrastructure engineering Jay Parikh at yesterday's Open Compute Summit.
The prototype storage cabinet reportedly holds 10,000 Blu-ray Discs for a petabyte of data. The idea is to store rarely accessed files, such as backups of users' photos and videos, and not the primary copies that need to be on faster storage systems so they can be accessed immediately.
Facebook expects to eventually increase the capacity of each cabinet to 5 petabytes. According to GigaOm, Parikh also revealed that "the first site is now in production and storing 30 petabytes of data, but a second will be coming online soon. Within a couple of months, Facebook expects to have 150 petabytes of data in cold storage, which is just a fraction of the 3 exabytes each facility is designed to house."
The prototype would have to be using 100GB Blu-ray Discs to hold a petabyte on 10,000 discs. The more common and much cheaper 50GB Blu-Ray Discs would seem to be more cost-effective based on consumer prices, but Facebook obviously buys through different channels. We've asked Facebook for more information and will provide an update if we get one.
Separately, Facebook said last year that it's considering the use of flash for cold storage. That would seem counterintuitive, but Facebook's idea is to use "the worst flash possible" to reduce costs, knowing that quality is less of a concern because cold storage devices don't need to be written over many times.